Circuit controller



March l0, 1931. L. w. BLYMYER CIRCUIT com-ROLLER Filed oct. l1o, 1927 2 Sheets-Sheet l Illlllllllllll lllllllllllll March 10, 1931. W BLYMYER i 1,795,707

CIRCUIT CONTROLLER Filed Oct. -10, 1927 2 Sheets-Sheet 2 Worf? 6,3/

Patented Mar. 10, 19,31

UNITED vsi',.ii'i'fiis LAFAYETTE W, BL'YMYER, or `Los* ANGELES, cALIFoRNIA CIRCUIT CONTROLLER Applicationiiledctober 10, 1927. Serial No. 225,373.

This invention has to do generally with circuit controllers, and may be considered as a resistance controller for controlling and maintaining constant the resistance andrcurrent flow of a variable resistance circuit.

The invention may be applied to advantage in a situation Where the controlling resistance element and the controlled resistanceelement, or, expressed otherwise, thel varying resistance and varied resistance, respectively, are one and the same, as the carbonsor electrodes of an arc light; or in a situation Where the controlling or varying resistance is other than the controlled or varied resistance as when a rheostat is in circuit Witha variably loaded motor. In the latter case, the motor is the varying or controlling element and the i'heostat is the varied or controlled element. Theinvention may also be considered as a novel arrangement for actuatingA a circuit controlling member. For instance, it is adapted to actuate mechanism for feeding or retracting the carbons (movement of which controls the arc voltage) of an arc lamp, or

which may be adapted to Vactuate .a D. C;

generator voltage regulator.

Irrespective of its use, the invention con-` templates an arrangement'vvhich is of a simple nature yet extremely sensitive and accurate. rIts characteristics may be described to better advantage by reference to a typical situation, from an understanding of Which those skilled in the art vvill readily appreciate how it be adaptedto other situations. Since the invention is capable of embodiment in an arc light with particular advantage, I

have chosen to present such an embodiment as a preferred one, though this is not to be y considered as limitative on the invention, cona sidered in its broader aspects. It will be understood that Whether the arc light be used for the projection of motion pictures for the purpose of villuminating scenes to be photo A graphed, or for any otherpurpose, the invention may be applied .with benefit, though it is especially beneficial when utilized .vconnection With thestriking and feed of carbons of scene-illuminating lamps Where yit is lof greatV importance to maintain a constant,

steady illumination. y y 1 The controller includes a pair of electric motors connected through a differentialto the element to be controlled. In the .preferred embodiment of theinvention, it is one or more of the carbone with V,which the motors are connected through the differential, though it Will be understood that in other embodiments of the inventionthe elements to be controlled may be of a nature quite different. v

I am avvare that a' single motor has been employed heretofore'in a manner to operate through a differential to feed the carbons together, thoughV such installations have required the use of mechanically operatedjgov ernorsfor controlling the differential move-` `ment. Furthermore, such installations necessarily require manual striking of the arc since the motor is adapted only to move the carbons toward onev another and therefore cannot be employed for establishing an arc gap. Onthe other hand, by virtueof my arrangement, the motors are adapted not only to maintain an arc gap of predetermined length after thearc has been struck, but also l to strike the arc automatically, that is, When a control switch is closed the carbonsvare'first fed'together until they contact and then auto-f, maticallyspread apart until the arc gap isof predetermined length. Thereafter, this gap is` automatically maintained by the lfeeding together ofthe carbons as the carbon tips are consumed.

It is Well known,'ofl`course, .that arcat Va given amperage operates most eliiciently` with the carbon tips a given distance apart and my device is adaptedtomaintain said' tips at saidgiven distance. 1 y One of the moto-rs is connectel `across the rheostat or gridof the are', While the other l(the distancevarying With the amperage) V` motoris connected across the are. Consequently, variations in grid andare voltages affect the operation of the motors, and the general arrangement is such that this condition brings about the above described results. Y

The details of the arrangement may be discussed to better advantage in the following specification, but it may be said here that it has been found that this comparatively simple arrangement functions" in a manner to give to the are light great efficiency of operation, practically no attention being required of the operator except to replenish the` carbons.

Other features of novelty and objects of` the invention will'bei made apparentin the following detailed description, referencemeing had to the 'accompanying drawings, in which:

Fig. 1 is a side view'of an embodiment of myfinvention;y

u Fig. 2 yis a reduced plan view of F ig. 1;

Fig. 3 is a section on line 3 3 of Fig.k 1; Fig. 4 is a wiring diagram showing a preferred method of connecting the various ele- Vments electrically, Y

Figf is a View showing another adaptation of theinvention; and

Fig. 6 is a wiring diagram showing the y device of Fig. 5 in circuit.

` As stated at theo'utset, `the following descript-ion of a particular and preferred embodiment of the invention is not to be con- Sidered as limitative Abut rather, as illustrative, and the sameview is to be taken of the construction details' of the carbon feeding mechanism" here described as'being used in connection Vwith V,this i preferred embodiment.l

Forl instance, thoughl have herefsliown a mounting adapted to take two'gsets of carbonsfthe carbons of "each set both being moved by the feeding' and retractive mechanism, `it will be understood thev invention is equally applicable lamps having only one 01""nifore' thantwo sets of carbons, or to installationswhere only one carbonof a positivef'and negative pair is moved by the feeding'a'n'd retractive' n'ieclianism. i l

Numeral l() designates a base from which uprights 11,12'e21tend. These uprights support' alead screw 13 and a pair of guide rails or rods 16, therailspreferably being equispaced' from'the leadnscrew and being axially parallel therewith; Since the illustrated v`Mielianisni is Aadapted to feed andretract ,no both the positive and negative electrodes and since it is desirable that the movement given Vto `the electrodes from a singlemember i3, a Ygiven longitudinal extent of lead screw carries lright hand threads andv another por-i tion carries left hand threads. Forcinstance,

lead screw 13 has right left hand threads 13. 'c n Electrodev carriers 19 an d 2O are mounted hand threads 17 y and on guide rails 16 for sliding movement 1ongitudinally therealong, and they are provided with lugs or teeth 21 which engage the threadsof the lead screw, it following that rotation of the latter simultaneously moves the carriages toward or awa-y from each one direction or the other moves the positive `and the. negatiye .carbons .toward 0r away 'from' one aiiother. Siiice'the positive car- .lgol'lsarecponsumed more quickly than are the negative, and since it is desirable to keep the .point ,of illumination k or arc fixed, threads 18 are preferably coarser than threadsl', the ratio beingsuch that the positive electrodes are fed just enough Vfaster'than the ne ative to compensate the difference in rate o sump'ti'on.vv v

Lead screw 13 carries a gear 28 which is in mesh with a spur gear y29, the latter being non-rotatablyV mounted on af coaXia-l eXtension 30a of cylindric housing 30Vof the differential gearing device generally indicated at 31. The housing, .in turn, is rotatably mounted on" axially alined shafts 32 and 33 which are journaled in uprights 12a and 12, respectively. I These shafts 4carry bevel -gears 34 and `35, respectively, which are located within housing' 30 and mesh with planetary pinions 36. Pinions 36 are mounted for rotationy on spindles37, the'- latter being supported byy housing 30.V Shaft 33 carries a worm gear l33 which operatively engages worm 39 directly driven by motor A., Shaft V32 carries a worm gear 40 which is adapted to be driven by worm 41, the latter being direct-connected to motor-B.

The normal direction of rotations of the motors and the driving rconnection between them and the differential are such that with the motors operating .at the same effective speed, pinions 36 rotate idly and housing 30 remains stationary. However, when onemotor has greater effective speed than the other, pinions 36 arecaused to plz-metete, the

shaftswhich is controlling upon the difierential operation, the actual speed of each shaft voltages, these are not to be considered at vall as limitative on the invention, sincefthey'are l arbitrarily chosenjin order to point out a'spe cific example fromwhichv a full understanding of the principles of operation may be had. F or instance, it will beV assumedthat motor A is a variable speed motor kdesigned to run at 500 R. P. M. on thirty-seven volts,I and motor B a variable speedmotor adapted to run at 1000 R. P. M. on seventy-three volts. For convenience, the voltage given maybe termed normal'voltagesl ofthe respectivev motors and the angular velocities given as the .normal speeds of the motors. a' Since worm `wheels38 and 40 are in the ratio of l'to 2, it will be seen kthat shafts 33 and 32 are rotated at equalspeeds when the motors are driven at their respective normal speeds under normal voltage. Thus, when the voltages ofthe twomotor circuits are normal, the effective speeds of the two motors are the same, though the actual speed ofmotor B is twice that of motor A. VViththe motors thus running in balance,it will be seen that pinions 36 idle and housing 30 remains stationary sono movement is transmitted to the lead screw and carbons. Howeven'as soon asthe .motors become unbalanced "due tovoltage variations fromV normal, 1t will be seen that pinions 36 will be caused to planetate in one direction or the other and the rotating housing will then drive lead screw 13 through pinion 29 and gear 28, the rotation Aofthe lead screw causing the carbons to move to-` ward or away from each other delinending upon which motor is running thefaster, as far as effective speed is concerned.

It may be stated Aat this point, that the mo tors preferably are'of a relatively slow speed type and their rotating parts are relatively light so as to'have as little'over-running proclivities as possible and be capable of responding instantaneously to voltage changes.

Tn Fig. 4 T have disclosed a preferred cirl cuiting, though it will be understood this may be changed in certain respects without departing from the spirit and scope of the in vention. The letter S indicates a source of electricity from which'extend main leads or constant potential wires 42 and 43. For purposes of ing to electrode 27 and also to the grid or' iixed'resistance 48 for the arc current. Wire 49 leads fromgrid 48 through line-control switch 50 to wire 43. lVVirei `llead'sV from description, it willbe assumed that vthe fullV line voltage is 110 volts. `Vsire 44 Vcrease the arc gap, the are volta-ge wire 44'to wire '51a which leads tothe field circuit 52 of motor B,'and wire 53 leads from the last-named'cir'cuit to wireV 54 and to wire 55, said wirefV 55 being connected into the field circuit 56 ofmotor A, there being a wire 57 fromcircuit 56 to wire 51a. Wire 54 leads tof wire 58 which ties vinto wire 49 and extendsto thev variable resistance or rheostat`59. "Wire 60a leads from the variable resistance through the armature circuit 60 of motor A, and wire6i leads from circuit 60 tofwire 47. i Wire 62Connects electrodes 24 and 26, and; wire 63 leads from electrode 23 to wire 42. y

The' oper-ation ofthe device may be deA scribedb'est by considering a typical cycle of operation, it being assumed first that switch 50 isopen and the negative carbons separated yfrom lthe positive carbons by virtue ofthe will be noted that motor A is connectedacross l the rheostat lor grid of the arcand that only when the arc is burning properly the arc voltage is'7 3 or normal and themotoris caused to run at normal eifective speed.

When the switch 50 is closed, motor B gets the full line voltage, (which is, of course7 greater than its normal voltage, i..e. 37 volts) except for thedrop caused by the normal resistance of grid 48 and consequently runs above normal eective speed. lOn the other hand, since *motor A is connected across the grid, it does not initially receive-any current. Thus, with motor A at rest and motor B runing above vnormal speed, the differential housing is rotated comparatively7 rapidly and the gear and lead screw connections are such that its directionof rotationis proper to revolve screw 13 ina directionl t'o feed the car-A bons together.V `As soon as'the carbons touch, i

thevoltageV across the'arc drops Vbelow normal, and rises across the grid. As is evident, this variation in voltages slows motor B be-Y low normal speed and motor A starts up and runs above normali speed because it ,isshunted across grid 48. Y, This action reverses the direction of rotation of housing 30 and of lead screw 13, the carbons, which may bev considered as circuit controlling as well as circuit controlled members, thus' being drawn apart orretracted. As 'soon as'the carbons are Iat such a distancerapart that the arcvoltage is proper, both motors get theirfno'rmal voltage and therefore -run'at normal speedor in'balance.' Consequently, housing 30 remains stationary, vand no movement is imparted to the carbon carriers until there is a variation in this arc voltage. Y Y 1 lVhen the carbons burn awayand thus inrisesand the voltage across the grid lowers. creases the'speed of motor B above normal,

andreduces the speed of motor A below nor- Y mal, 'causing the' dierential housing 30 to ro- This in-v j Y soon asthe gap is restored to ,proper length,

iii)

the motors again receive normal voltage and vagain-run at normal speed., with the result set forth above. and circuit are so sensitive that the carbons are feeding together practically constantly, but this feed is so even that it is almost uni noticeable and the light value of the'farcremain-s practically constant, to obvious advantage. Y

It will thus be seen that the device is adaptedto strike the arc automatically and then maintain the are gap constant, it being noted Y that the speed of the carbon carriers during striking is'much greater than when they are fed tovether durin eriods of burnin@ since D 2D yb during the striking operation motor A holds gear stationary, while, during the normal feeding, said motor is running, though usually ata little less than atV -normal speed and gear 35 is rotating. v

It maybe stated that while the wiring diagram shows the field coils of the motors connected across the full line voltage, the armature of motor A across the grid and the :armature of motor B acrossthe arc or rather, acrosstwo arcs in series, it will be understood this is not `'essential to successful operation of the arc control, though is particularly eH- cientsince the speed change is greater for a slight change in voltage than would be the case were a motor to be used as a'straight shunt motor. lThus various -motor circuitings may be utilized, and for this reason the motor circuits connected across thearc and grid to be operated and controlled bythe respective potentials thereacross may be consid-g ered as the speed-controlling motor circuits.

Motor B may be considered as the carbon advancing or feeding member, and motor A asthe carbon retractor.

It will be readily appreciated that the above described control may be adapted to control a single, double or triple are taking Aany chosen amperage and voltage, it only being necessary to Vvary the motors to run normally at predetermined voltages andconnectingthem to the differential and carbons with the proper drive-connection ratios.-

In Figs. 5 and 6, I have shown a slight variation wherein a motor M, which may be considered as operating under variable load, is introduced in the circuitvbetween, for instance. wires 68 and 42and a variable resistance R substituted for the carbons or electrodes of the Vother figures. The rest'. of the hook-up may' be as described above, the situ- Inactual'operation, the motors" controlling energizing Y lacross the resistance and the lother motor havi ation'here.- being that motor MV-is tbewryll'g or controllingresistance and `rheostat R is the varied or controlled resistance. This rheostat may be of any type embodying a movable control element, in rthis case said element 4beingin theform of a carbon plunger 65 mounted'on carrier 20 and `adapted to be reciprocated through the stationarily mounted potv66 having a graphite filler. lt will be seen that variations in the resistance offered -by `the motor due to its varying load servesto move carbon plunger into and out of pot 66 in a manner equivalent tothe indesign` structure andarrangement mayf be made` without, departing vfromthe spirit and scope of said claims. f

I claim: Y

1. In'an arc lamp, a pair 'of electrodes in circuit with a pair of constant potential mains, a resistance element in one of ythe mains for controlling the arc current, one of Y said electrodes being mounted for `movement toward and away from the other, a pair of motors, one of themotors havmga speedcircuit connected ing a speed-controlling energizing circuit connected across the arc gap, a pair of gears, one driven by each motor, a planetary gear meshing withthe two gears, and means operatively connecting the planeta-ry gear and said one electrode whereby planetation of said gear moves said one electrode with relation to the other.

2. In an arc lamp, a pair `of electrodes in circuit with apair of constant potential mains, aresistance element. in one of the mains forgcontr'olling the'arc current, said electrodesbeing mounted for movement .to-

ward andaway from each other, a pair of motors, one 'of the motors having a speedcontrolling lenergizing circuit connected across the resistance and the other motor having a Vspeed-controlling energizing circuit connected across'the arc gap, a pair of gears, one driven'by each motor, a planetary gea-r meshing withthe two gears, and means operatively connecting,r the planet-ary gear and said electrodes whereby `planetation of said gea-r moves said eachother.

3. In the art described, apair of electrodes in circuit with potential mains. one of the electrodes being movable towardand away from the otherfdiiferential gearing for so moving-the electrodes. and means for operating the gearing, said. means embodying a electrodes with relation toV lili ist

pair of Variable speed motors, and electrical circuit-ing whereby one of said motors is automatically operated in direct speed responsiveness to the arc voltage across the electrodes, and whereby the other ofsad motors is automatically operated in inverse speed 'c responsiveness to the are voltage Vacross lthe electrodes. v In Witness that I claim the foregoing I have hereunto subscribed my neme this 16th day of May, 1927.

LAFAYETTE W. 'BLYMYER 

